Ukrainian President Volodymyr Zelensky said Thursday that Russia needed to "feel" the consequences of its war as a major Ukrainian incursion across the Russian border stretched into a third day.
Pro-Kyiv forces stormed into Russia's southwestern Kursk region on Tuesday morning, deploying around 1,000 troops and more than two dozen armoured vehicles and tanks, according to the Russian army.
It appears to be the most significant Ukrainian attack into Russia since the war began, with independent analysts suggesting Kyiv's troops had advanced up to 10 kilometres (six miles) into Russia.
"Russia brought the war to our land and should feel what it has done," Zelensky said in his evening address, without directly referring to the offensive.
"Ukrainians know how to achieve their goals. And we did not choose to achieve our goals in the war," he added.
Russia's defence ministry said Thursday its troops were "continuing to destroy" armed Ukrainian units and were using air strikes, rocket and artillery fire to try to push them back.
It said it had rushed in reserves and was "thwarting attempts to break through" deeper into the Kursk region. The independent US-based Institute for the Study of War (ISW) said Ukraine had made significant territorial gains in the first two days of the incursion.
"Ukrainian forces have made confirmed advances up to 10 kilometres (six miles) into Russia's Kursk Oblast amid continued mechanised offensive operations on Russian territory," it said in its latest update.
"The current confirmed extent and location of Ukrainian advances in Kursk Oblast indicate that Ukrainian forces have penetrated at least two Russian defensive lines and a stronghold," it added.
Kyiv has not officially taken responsibility for the operation, but an aide to Zelensky said Moscow was to blame for the incursion. "The root cause of any escalation, shelling, military actions, forced evacuations and destruction of normal life forms -- including within the Russian Federation's own territories like Kursk and Belgorod regions -- is solely Russia's unequivocal aggression," presidential aide Mykhailo Podolyak said Thursday on social media.
Without mentioning the Kursk attacks, Zelensky said Wednesday: "The more pressure we put on Russia ... the closer we will get to peace. A just peace through just force." Russian President Vladimir Putin has called it a "large-scale provocation" by Kyiv and Russia's top general vowed on Wednesday to crush the incursion.